A354190 a(n) = phi(A267099(sigma(n))), where A267099 is fully multiplicative involution swapping the positions of 4k+1 and 4k+3 primes.

1, 4, 2, 12, 4, 8, 4, 8, 6, 20, 8, 24, 12, 16, 16, 40, 20, 24, 4, 48, 16, 40, 16, 16, 40, 48, 8, 48, 8, 80, 16, 240, 32, 100, 32, 72, 28, 16, 48, 40, 48, 64, 32, 96, 24, 80, 32, 80, 112, 160, 80, 156, 100, 32, 80, 32, 16, 40, 16, 192, 40, 64, 24, 148, 96, 160, 20, 240, 64, 160, 80, 48, 22, 112, 80, 48, 64, 192, 16

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..19683

Formula

a(n) = A354102(A000203(n)) = A000010(A267099(A000203(n))).

a(n) = A354191(n) + A354102(n).

Prog

(PARI) A354190(n) = eulerphi(A267099(sigma(n))); \\ Uses the program given in A267099.

Crossrefs

Cf. A000010, A000203, A267099, A354102, A354191.

Cf. also A062401.

Sequence in context: A010318 A188134 A226725 * A137447 A353749 A077015

Adjacent sequences: A354187 A354188 A354189 * A354191 A354192 A354193

Keyword

nonn

Author

Antti Karttunen, May 19 2022

Status

approved